Rules of thumb in no logical order -

i) Longer the head the further you can fly it -
ii) 11 Yards ( or 10m) is about the longest you want for boat fishing - ( otherwise you'll whack your lure on the thwarts a fair bit plus it takes an extra false cast in the sequence )
iii) If the rod is say an 8/9 use a 10 at 11m as a start point .
iv) The heavier the head - the easier it is to make distance (air resistance)
v) Probably a waste of time - any system much below a 9# outfit
vi) Don't use braided loops as connector between head and running line - strip to core , sew and whipped loops last - braided loops don't .
vii) Get yourself a decent line tray or raft !

Best wishes

Steve P